Archaean ophiolite

Of relevance here are those Archaean ophiolites which may contain an ultramafic mantle section. One possible example is the Dongwanzi ophiolite in China (Kusky et al., 2001) from which harzburgite tectonites up to 70 m thick, dunites, pyroxenites and wehrlites have been described. These rocks also contain podiform chromitites with nodular textures, thought to be unique to mantle chromitite occurrences (Kusky et al., 2001 Kusky, 2004). This ultramafic assemblage is interpreted as depleted mantle from which a basaltic melt has been extracted. 

Fripp, R.E.P. and Jones, M.G., 1997. Sheeted intrusions and peridotite-gabbro assemblages in the Yilgarn Crato, western Australia elements of Archaean ophiolites. In De Wit, M.J. and Ashwaal, L.D. (eds), Greenstone Belts. Oxford University Press, Oxford, pp. 422-37. 

Kusky, T.M., Li, J.-H., and Tucker, R.D., 2001. The Archaean Dongwanzi ophiolite complex, north China Craton 2.505 billion-year-old oceanic crust and mantle. Science, 292, 1142-5. 

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